Often, there is a need to interconnect various components together in an electrical circuit. For example, in an aircraft, the generation and distribution of electrical power is controlled by an electrical power control unit (EPCU), which in turn includes a number of circuit boards (specifically, printed wiring boards or PWB's), a motherboard and a plurality of bus bars. Each PWB includes a first side mounted in an edge connector carried by the motherboard and control signals are passed through such edge connectors. In a first design, the bus bars are mounted on the motherboard and are coupled by further connectors to the PWB's. This arrangement has the Electrical disadvantage of locating the power conducted by the bus bars close to the control signals. In addition, access to screw type bus bar connections is difficult to achieve and the plug in connections to the bus bars are blind and also difficult to achieve. Still further, the need to secure two separate connectors (i.e., one power and one control) to each PWB can result in assembly tolerance problems or thermal mismatch which could result in unacceptable stress. Also considered was an approach in which multiple pins in the edge connector that also conducts the control signals; however, in the case where several daughter boards were used, this undesirably resulted in a very large combined current in the motherboard
In a further arrangement intended to overcome at least some of the foregoing problems, the PWB's are interconnected at a second side opposite the motherboard by the bus bars. In this fashion, the control signals are advantageously kept remote from the power conducted by the bus bars. In one such design, each bus bar is coupled by screws extending through holes therein to threaded sockets carried on the second sides of the PWB's. In an alternative design, pins are carried by the bus bars and extend into unthreaded sockets carried by the PWB's. While this arrangement is effective to eliminate some of the problems noted above, there still remain the assembly tolerance and thermal mismatch problems resulting from the rigid connection of each PWB to the motherboard and the bus bars.